Summary: The LACU assists the NIAMS IRP investigators with their research involving animals. NIAMS animals are housed in animal facilities located on the NIH campus, including the NIAMS LACU facility located in Building 10, room 9C127 (the Ambulatory Care Research Facility (ACRF)), as well as in Buildings 6B, 10A, 50 and Building 14. NIAMS animal users work primarily with mice and rats. The NIAMS IRP Animal Program has oversight for 24 Animal Study Proposals (ASPs) using mouse and rat models. The LACU assists researchers with preparing ASPs through a thorough peer-review process and has 3 members (1 alternate and 2 voting) on the NIAMS Animal Care and Use Committee (ACUC). The LACU maintains an up to date and detailed animal inventory, the foster colony, and the sentinel program for the IRP animals. An approximately 1-hour training program, administered by the LACU colony manager, familiarizes all new NIAMS investigators and PIs with NIH and NIAMS-specific guidelines, a general overview of rodent colony management, and rodent biology as it relates to breeding and research guidelines. IRP project areas include arthritis, allergic rhinitis and other receptor-induced cellular responses, recombination/chromatin remodeling using AID transgenic mice, familial Mediterranean fever (FMF), and TNF receptor-associated periodic syndrome. Research involves muscle and related diseases (experimentation with N-RAP protein, glycogen storage disease Type II, SIRT1 gene, myofibril assembly, and myositis) and sub-cellular organelles and cytoskeleton in skeletal muscle, as well as in vitro experiments examining retroviral transduction, bone marrow transplantation, and epidermal differentiation using fetal and adult skin tissues. Many of the institutes studies involve apoptosis and autoimmunity, as well as cartilage studies focused on tissue-engineered cartilage, chondrogenesis, GDF-F, COMP and osteoarthritis. The NIAMS program continues to meet all accreditation requirements set forth by Association for Assessment and Accreditation of Laboratory Animal Care International (AAALAC), including the most recent successful NIH-wide visit in June of 2017.